I´m using Yapdatabase as storage engine in my iOS-application, and I need an index representing multiple values of the same property of an object.
Example: I´m storing car objects in my Yapdatabase. Most of my car objects have multiple colors, but I´d like to efficiently retrieve all yellow cars.
I´m somewhat familiar with YapDatabaseSecondaryIndexes, but I´ve not been able to fit that into my scenario.
How may I efficiently retrieve yellow cars?
There are a couple options. If you're only dealing with a handful of colors, then you can still use YapDatabaseSecondaryIndex. You could configure your index to include a field for each color.
YapDatabaseSecondaryIndexSetup *setup = [[YapDatabaseSecondaryIndexSetup alloc] init];
[setup addColumn:@"red" withType:YapDatabaseSecondaryIndexTypeInteger];
[setup addColumn:@"blue" withType:YapDatabaseSecondaryIndexTypeInteger];
...
And then each car simply sets the "flags" for each color.
If you're dealing with a lot of different colors, then it may be more effective to use the FullTextSearch extension instead. Basically, you're going to create a string for each car that contains all the colors, and hand that string to the FullTextSearch extension. And then you can simply issue queries for cars that contain "yellow".
